Air in heating system Help and information on all topics relating to your central heating, air conditioning and ventilation issues.

[mally434]

I have a wall mounted heat only condensing boiler with 3 way motorised valve and combined feed/vent and 8mm plastic pipes. I always have to bleed the rad. in bedroom. Can anyone please advise ? Many thanks. Malcolm

[htg engineer]

is this a pressurised system ?

If you get continuous problems with one radiator and the rest are fine - then it is likely to be a small leak either on one of the radiator valves, or on one of the pipes under the floor.

You could try adding leak sealer to the system which will seal any small leaks.

[mally434]

Many thanks for your response HTG Engineer. The boiler is not a combi and therefore not pressurised. It does not appear there is a leak as nothing is showing on ceiling. I have been told that it may be the quality of the plastic 8mm pipe insomuch as it may be porous thereby air is permeating through the pipe walls. Is this possible ? the heating was fitted in my new house 10yrs ago. Can you please suggest a branded leak sealer. Many thanks Malcolm.